Retention Characteristics And Policy As Suggested By California School Administrators And Teachers

Problem. There has been no definite conclusions in the literature as to the benefit or harm of retaining students in grade. With the California Legislative Mandate of SB 813, school districts are now required to have policies in effect for the promotion or nonpromotion of students. This study reviewed retention characteristics currently used in retention policy, those mentioned in literature, and the perceptions of administrators and teachers as to the value of these characteristics in retention. A model retention policy was developed from the study. Purpose. The purpose of the study was to determine if there were differences between teachers and administrators regarding their perceptions of the importance of specific characteristics used in retention policy. Based on the available research, a model policy that suggests guidelines for determining the retention of a student in grade was developed. Procedure. Questionnaires were sent to 93 California school districts. Ninety-three administrators and 372 teachers were surveyed. Three hundred and five questionnaires were returned. The survey results were analyzed to compare administrator and teacher responses to the importance of retention characteristics. Comparisons were also made between urban, rural and suburban school districts. The Chi Square statistics were used for all comparisons with the .05 level of confidence chosen for all inferential tests. Findings. Administrators and teachers consistently agreed on the five most common reasons that should be considered in a retention policy. These were academic achievement, teacher evaluation of student progress, emotional maturity, previous retention and parental support to the recommendation for retention. Overall, there was no significant difference between teachers and administrators in their perceptions of the importance of individual retention characteristics. The items that had significant differences were low importance items. There was no significant difference between teachers and administrators by districts. Recommendations. This study should be replicated since many teachers did not indicate their grade levels on the questionnaires. A study should be made to help classify educational terms such as academic achievement and emotional maturity. Long term studies should be done to follow up students who have been retained to determine if the retention was beneficial. A study should be done to better determine the entry age of students and the effect entry age has on retentions

Discerning the clinical relevance of biomarkers in early stage breast cancer

Purpose Prior data suggest that breast cancer patients accept significant toxicity for small benefit. It is unclear whether personalized estimations of risk or benefit likelihood that could be provided by biomarkers alter treatment decisions in the curative setting. Methods A choice-based conjoint (CBC) survey was conducted in 417 HER2-negative breast cancer patients who received chemotherapy in the curative setting. The survey presented pairs of treatment choices derived from common taxane- and anthracycline-based regimens, varying in degree of benefit by risk of recurrence and in toxicity profile, including peripheral neuropathy (PN) and congestive heart failure (CHF). Hypothetical biomarkers shifting benefit and toxicity risk were modeled to determine whether this knowledge alters choice. Previously identified biomarkers were evaluated using this model. Results Based on CBC analysis, a non-anthracycline regimen was the most preferred. Patients with prior PN had a similar preference for a taxane regimen as those who were PN naïve, but more dramatically shifted preference away from taxanes when PN was described as severe/irreversible. When modeled after hypothetical biomarkers, as the likelihood of PN increased, the preference for taxane-containing regimens decreased; similarly, as the likelihood of CHF increased, the preference for anthracycline regimens decreased. When evaluating validated biomarkers for PN and CHF, this knowledge did alter regimen preference. Conclusions Patients faced with multi-faceted decisions consider personal experience and perceived risk of recurrent disease. Biomarkers providing information on likelihood of toxicity risk do influence treatment choices, and patients may accept reduced benefit when faced with higher risk of toxicity in the curative setting

Constraining mean-field models of the nuclear matter equation of state at low densities

An extension of the generalized relativistic mean-field (gRMF) model with density dependent couplings is introduced in order to describe thermodynamical properties and the composition of dense nuclear matter for astrophysical applications. Bound states of light nuclei and two-nucleon scattering correlations are considered as explicit degrees of freedom in the thermodynamical potential. They are represented by quasiparticles with medium-dependent properties. The model describes the correct low-density limit given by the virial equation of state (VEoS) and reproduces RMF results around nuclear saturation density where clusters are dissolved. A comparison between the fugacity expansions of the VEoS and the gRMF model provides consistency relations between the quasiparticles properties, the nucleon-nucleon scattering phase shifts and the meson-nucleon couplings of the gRMF model at zero density. Relativistic effects are found to be important at temperatures that are typical in astrophysical applications. Neutron matter and symmetric matter are studied in detail.Comment: 50 pages, 21 figure

Discovery and Follow-up Observations of the Young Type Ia Supernova 2016coj

The Type~Ia supernova (SN~Ia) 2016coj in NGC 4125 (redshift $z=0.004523$) was discovered by the Lick Observatory Supernova Search 4.9 days after the fitted first-light time (FFLT; 11.1 days before $B$-band maximum). Our first detection (pre-discovery) is merely $0.6\pm0.5$ day after the FFLT, making SN 2016coj one of the earliest known detections of a SN Ia. A spectrum was taken only 3.7 hr after discovery (5.0 days after the FFLT) and classified as a normal SN Ia. We performed high-quality photometry, low- and high-resolution spectroscopy, and spectropolarimetry, finding that SN 2016coj is a spectroscopically normal SN Ia, but with a high velocity of \ion{Si}{2} $\lambda$6355 ($\sim 12,600$\,\kms\ around peak brightness). The \ion{Si}{2} $\lambda$6355 velocity evolution can be well fit by a broken-power-law function for up to a month after the FFLT. SN 2016coj has a normal peak luminosity ($M_B \approx -18.9 \pm 0.2$ mag), and it reaches a $B$-band maximum \about16.0~d after the FFLT. We estimate there to be low host-galaxy extinction based on the absence of Na~I~D absorption lines in our low- and high-resolution spectra. The spectropolarimetric data exhibit weak polarization in the continuum, but the \ion{Si}{2} line polarization is quite strong ($\sim 0.9\% \pm 0.1\%$) at peak brightness.Comment: Submitte

Baryon-baryon interactions in the SU6 quark model and their applications to light nuclear systems

Interactions between the octet-baryons (B8) in the spin-flavor SU6 quark model are investigated in a unified coupled-channels framework of the resonating-group method (RGM). The interaction Hamiltonian for quarks consists of the phenomenological confinement potential, the color Fermi-Breit interaction with explicit flavor-symmetry breaking (FSB), and effective-meson exchange potentials of scalar-, pseudoscalar- and vector-meson types. The model parameters are determined to reproduce the properties of the nucleon-nucleon (NN) system and the low-energy cross section data for the hyperon-nucleon (YN) interactions. The NN phase shifts and many observables for the NN and YN interactions are nicely reproduced. Properties of these B8 B8 interactions are analyzed through the G-matrix calculations. The B8 B8 interactions are then applied to some of few-baryon systems and light Lambda-hypernuclei in a three-cluster Faddeev formalism using two-cluster RGM kernels. An application to the three-nucleon system shows that the quark-model NN interaction can give a sufficient triton binding energy with little room for the three-nucleon force. The hypertriton Faddeev calculation indicates that the attraction of the Lambda N interaction in the 1S0 state is only slightly more attractive than that in the 3S1 state. In the application to the alpha alpha Lambda system, the energy spectrum of 9 Lambda Be is well reproduced using the alpha alpha RGM kernel. The very small spin-orbit splitting of the 9 Lambda Be excited states is also discussed. In the Lambda Lambda alpha Faddeev calculation, the NAGARA event for 6 Lambda Lambda He is found to be consistent with the quark-model Lambda Lambda interaction.Comment: 77 pages, 33 figures, review article to be published in Prog. Part. Nucl. Phy

Leaf: Modularity for Temporary Sharing in Separation Logic (Extended Version)

In concurrent verification, separation logic provides a strong story for handling both resources that are owned exclusively and resources that are shared persistently (i.e., forever). However, the situation is more complicated for temporarily shared state, where state might be shared and then later reclaimed as exclusive. We believe that a framework for temporarily-shared state should meet two key goals not adequately met by existing techniques. One, it should allow and encourage users to verify new sharing strategies. Two, it should provide an abstraction where users manipulate shared state in a way agnostic to the means with which it is shared. We present Leaf, a library in the Iris separation logic which accomplishes both of these goals by introducing a novel operator, which we call guarding, that allows one proposition to represent a shared version of another. We demonstrate that Leaf meets these two goals through a modular case study: we verify a reader-writer lock that supports shared state, and a hash table built on top of it that uses shared state

Epidemiologic investigation of immune-mediated polyradiculoneuropathy among abattoir workers exposed to porcine brain

Background In October 2007, a cluster of patients experiencing a novel polyradiculoneuropathy was identified at a pork abattoir (Plant A). Patients worked in the primary carcass processing area (warm room); the majority processed severed heads (head-table). An investigation was initiated to determine risk factors for illness. Methods and Results Symptoms of the reported patients were unlike previously described occupational associated illnesses. A case-control study was conducted at Plant A. A case was defined as evidence of symptoms of peripheral neuropathy and compatible electrodiagnostic testing in a pork abattoir worker. Two control groups were used - randomly selected non-ill warm-room workers (n = 49), and all non-ill head-table workers (n = 56). Consenting cases and controls were interviewed and blood and throat swabs were collected. The 26 largest U.S. pork abattoirs were surveyed to identify additional cases. Fifteen cases were identified at Plant A; illness onsets occurred during May 2004–November 2007. Median age was 32 years (range, 21–55 years). Cases were more likely than warm-room controls to have ever worked at the head-table (adjusted odds ratio [AOR], 6.6; 95% confidence interval [CI], 1.6–26.7), removed brains or removed muscle from the backs of heads (AOR, 10.3; 95% CI, 1.5–68.5), and worked within 0–10 feet of the brain removal operation (AOR, 9.9; 95% CI, 1.2–80.0). Associations remained when comparing head-table cases and head-table controls. Workers removed brains by using compressed air that liquefied brain and generated aerosolized droplets, exposing themselves and nearby workers. Eight additional cases were identified in the only two other abattoirs using this technique. The three abattoirs that used this technique have stopped brain removal, and no new cases have been reported after 24 months of follow up. Cases compared to controls had higher median interferon-gamma (IFNγ) levels (21.7 pg/ml; vs 14.8 pg/ml, P<0.001). Discussion This novel polyradiculoneuropathy was associated with removing porcine brains with compressed air. An autoimmune mechanism is supported by higher levels of IFNγ in cases than in controls consistent with other immune mediated illnesses occurring in association with neural tissue exposure. Abattoirs should not use compressed air to remove brains and should avoid procedures that aerosolize CNS tissue. This outbreak highlights the potential for respiratory or mucosal exposure to cause an immune-mediated illness in an occupational setting

On the grammar of politics—or why conservatives prefer nouns

Previous research indicates that political conservatism is associated with epistemic needs for structure and certainty (Jost et al., 2003) and that nouns elicit clearer and more definite perceptions of reality than other parts of speech (Carnaghi et al., 2008). We therefore hypothesized that conservatives would exhibit preferences for nouns (vs. verbs and adjectives), insofar as nouns are better suited to satisfy epistemic needs. In Study 1, we observed that social conservatism was associated with noun preferences in Polish and that personal need for structure accounted for the association between ideology and grammatical preferences. In Study 2, conducted in Arabic, social conservatism was associated with a preference for the use of nominal sentences (composed of nouns only) over verbal sentences (which included verbs and adjectives). In Study 3, we found that more conservative U.S. presidents used greater proportions of nouns in major speeches, and this effect was related to integrative complexity. We discuss the possibility that conservative ideology is linked to grammatical preferences that foster feelings of stability and predictability

A Realistic Description of Nucleon-Nucleon and Hyperon-Nucleon Interactions in the SU_6 Quark Model

We upgrade a SU_6 quark-model description for the nucleon-nucleon and hyperon-nucleon interactions by improving the effective meson-exchange potentials acting between quarks. For the scalar- and vector-meson exchanges, the momentum-dependent higher-order term is incorporated to reduce the attractive effect of the central interaction at higher energies. The single-particle potentials of the nucleon and Lambda, predicted by the G-matrix calculation, now have proper repulsive behavior in the momentum region q_1=5 - 20 fm^-1. A moderate contribution of the spin-orbit interaction from the scalar-meson exchange is also included. As to the vector mesons, a dominant contribution is the quadratic spin-orbit force generated from the rho-meson exchange. The nucleon-nucleon phase shifts at the non-relativistic energies up to T_lab=350 MeV are greatly improved especially for the 3E states. The low-energy observables of the nucleon-nucleon and the hyperon-nucleon interactions are also reexamined. The isospin symmetry breaking and the Coulomb effect are properly incorporated in the particle basis. The essential feature of the Lambda N - Sigma N coupling is qualitatively similar to that obtained from the previous models. The nuclear saturation properties and the single-particle potentials of the nucleon, Lambda and Sigma are reexamined through the G-matrix calculation. The single-particle potential of the Sigma hyperon is weakly repulsive in symmetric nuclear matter. The single-particle spin-orbit strength for the Lambda particle is very small, in comparison with that of the nucleons, due to the strong antisymmetric spin-orbit force generated from the Fermi-Breit interaction.Comment: Revtex v2.09, 69 pages with 25 figure